Function h2_c2_process

modules/http2/h2_c2.c:667–729

}

apr_status_t h2_c2_process(conn_rec *c2, apr_thread_t *thread, int worker_id)
{
    h2_conn_ctx_t *conn_ctx = h2_conn_ctx_get(c2);

    ap_assert(conn_ctx);
    ap_assert(conn_ctx->mplx);

    /* See the discussion at <https://github.com/icing/mod_h2/issues/195>
     *
     * Each conn_rec->id is supposed to be unique at a point in time. Since
     * some modules (and maybe external code) uses this id as an identifier
     * for the request_rec they handle, it needs to be unique for secondary
     * connections also.
     *
     * The MPM module assigns the connection ids and mod_unique_id is using
     * that one to generate identifier for requests. While the implementation
     * works for HTTP/1.x, the parallel execution of several requests per
     * connection will generate duplicate identifiers on load.
     *
     * The original implementation for secondary connection identifiers used
     * to shift the master connection id up and assign the stream id to the
     * lower bits. This was cramped on 32 bit systems, but on 64bit there was
     * enough space.
     *
     * As issue 195 showed, mod_unique_id only uses the lower 32 bit of the
     * connection id, even on 64bit systems. Therefore collisions in request ids.
     *
     * The way master connection ids are generated, there is some space "at the
     * top" of the lower 32 bits on allmost all systems. If you have a setup
     * with 64k threads per child and 255 child processes, you live on the edge.
     *
     * The new implementation shifts 8 bits and XORs in the worker
     * id. This will experience collisions with > 256 h2 workers and heavy
     * load still. There seems to be no way to solve this in all possible
     * configurations by mod_h2 alone.
     */
    c2->id = (c2->master->id << 8)^worker_id;

    if (!conn_ctx->pre_conn_done) {
        ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c2,
                      "h2_c2(%s-%d), adding filters",
                      conn_ctx->id, conn_ctx->stream_id);
        ap_add_input_filter("H2_C2_NET_IN", NULL, NULL, c2);
        ap_add_output_filter("H2_C2_NET_CATCH_H1", NULL, NULL, c2);
        ap_add_output_filter("H2_C2_NET_OUT", NULL, NULL, c2);

        c2_run_pre_connection(c2, ap_get_conn_socket(c2));
        conn_ctx->pre_conn_done = 1;
    }

    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,
                  "h2_c2(%s-%d): process connection",
                  conn_ctx->id, conn_ctx->stream_id);

    c2->current_thread = thread;
    ap_run_process_connection(c2);

    ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c2,